Process for imparting a transparent appearance to cotton fabrics.



GEOBG HEBERLEIN, 0F WATTWIL, SWITZERLAND.

PROCESS FOR IMPARTING A TRANSPARENT APPEARANCE TO COTTON FABRICS.

Specification'of Letters Patent. Patented Dec. 24., 1918.

No Drawing. Original application filed may 18, 1916, Serial No. 98,295. Divided and this application filed June 6, 1918. Serial No. 238,569.

To all whom it may concern:

Be it known that I, Gnone HEBERLEIN, a

citizen of the Swiss Republic, and resident of VVa'ttwil, Canton of St. Gall, Switzerland, have invented a new and useful Process for Imparting a Transparent Appearance to Cotton Fabrics, of which the followingls a full, clear, and exact specification. 1

This application is a divisional one of my application for Letters Patent Ser. No. 98295, filed May 18,1916.

It is known that by the action ofconcentrated sulfuric acid upon cotton, the latter acquires a parchment-like quality. It 1s also known that the action of the sulfuricacid is more intense if the cotton has been pre viously mercerized. For example, if a mercerized fabric be acted upon by sulfuric acid of over 505 Baum for a few seconds, the

said fabric acquires a highly transparent appearance. The U. S. Letters Patent N 0. 1144655, dated June 29, 1915, is based upon this observation. Similar changes in the cotton take place, if the fabric be first treated with sulfuric acid for a few seconds and then acted upon with concentrated soda-lye.

From the foregoing statement it is obvious that on the one hand the action of sulfuric acid is the more intense if the cotton has been previously treated with soda-lye and on the other hand that a cotton which has been subjected to the action of concentrated sulfuric acid comports itself differently during the subsequent treatment with soda-lye than in the case with cotton, which has not been thus previously treated.

I have now found that a still more enhanced transparency of cotton can be obtained by causing sulfuric acid of over 50% Baum and concentrated alkali lye to act upon the said fabrics several times alternately, the sulfuric acid being always letto act only for a few seconds.

In order to obtain this enhanced transparency of cotton it is necessary that one or other of the two reagents shall be employed at least twice with the intermediate action of the other agent, for example sulfuric acidsoda-lyesulfuric acid. In between the reactions the goods must be well washed and if desired,"subsequently dried.

It will be obvious that most various degrees of transparency are to be. obtained according. to the numberv of manipulations.

' Variations in the transparency of the fabric can also be obtained by more or less stretching the same in the longitudinal and transverse direction during one treatment or during several treatments that is to say by allowing it to shrink more or less.

Finally transparent pattern effects may be obtained by printing the alkali or the acid at one or more of .the operations only upon particular portions of the fabric, or by printing on particular portions of the fabric a resist (for instance gum thickening) either at the commencement of the treatment or between the first and the second or between two successive operations, the said. resist preventing a further reaction'of the alkali or the acid. Those portions which are not printed with alkali or acid or which have been reserved differentiate themselves from the printed or unreserved portions which have experienced a more thorough modification so that more or less sharp patterns are produced. Thus on a. fabric treated for a few seconds with sulfuric acid of over 505 Baum and washed out, patterns may be printed with concentrated soda lye, and afterward the fabric washed out and treated a-second time for a few seconds with sulfuric Baum and finally again between two'trea-tments with the other, the

sulfuric acid being allowed to act on the fabrics each time only for a few seconds and the fabrics being washed out after each treatment.

2. The herein described process for imparting to cotton fabrics a transparent appearance consisting in causing sulfuric acid of over 50% B. and concentrated alkali lye to act alternately and repeatedly upon the fabrics in such a manner that at least one treatment with concentrated alkali lye takes place between two treatments with sulfuric acid, these latter treatments during always only a few seconds and the fabrics being washed out after each treatment.

between two treatments with the other, the

sulfuric acid being allowed to act each time only for 'a few seconds and the fabrics being stretched at least during one of the said treatments and washed outafter each treatment. 1

4. The herein described process for producing transparent pattern efiectson cotton fabrlcs, conslsting 1n causmg sulfuric acld of over 50!; B. and concentrated alkali lye to act alternately and repeatedly upon the fabrics in such a manner that at least one treatment withconcentrated alkali lye takes place between two treatments with sulfuric acid, the sulfuric acid being allowed to act each time only for a few seconds and at least-at one of the said treatments the reagent used beingcaused to react only upon particular portions of the fabrics and the fabrics being washed out' after each. treatment. v

5. The herein described process for producing transparent pattern effects on cotton fabrics, consisting in causing sulfuric acid of over 50% Be. and concentrated alkali lye to act' alternately and repeatedly upon the fabrics in such a manner that a treatment with one of the said reagentstakes place between two treatments with the other, the sulfuric acid being allowed to act each time only for a few seconds and the fabrics being stretched at least during on'of the said treatments and at least at one of the said treatments the reagent used being causedto react only upon particular portions of the fabrics and thefabrics being washed out after each treatment. 7

In witness whereof I have hereunto signed my name this 24 day of April, 1918, in the presence of two subscribing witnesses.

GEQRG HEBERLEIN. lVitnessesi- I RALPH T. CHEsBRoUGH, FRANK FINNEGKE. 

